adk-python/tests/unittests/sessions/test_vertex_ai_session_service.py

# Copyright 2025 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import copy
import datetime
import re
import types
from typing import Any
from typing import List
from typing import Optional
from typing import Tuple
from unittest import mock

from dateutil.parser import isoparse
from fastapi.openapi import models as openapi_models
from google.adk.auth import auth_schemes
from google.adk.auth.auth_tool import AuthConfig
from google.adk.events.event import Event
from google.adk.events.event_actions import EventActions
from google.adk.sessions.base_session_service import GetSessionConfig
from google.adk.sessions.session import Session
from google.adk.sessions.vertex_ai_session_service import VertexAiSessionService
from google.api_core import exceptions as api_core_exceptions
from google.genai import types as genai_types
import pytest

MOCK_SESSION_JSON_1 = {
    'name': (
        'projects/test-project/locations/test-location/'
        'reasoningEngines/123/sessions/1'
    ),
    'create_time': '2024-12-12T12:12:12.123456Z',
    'update_time': '2024-12-12T12:12:12.123456Z',
    'session_state': {
        'key': {'value': 'test_value'},
    },
    'user_id': 'user',
}
MOCK_SESSION_JSON_2 = {
    'name': (
        'projects/test-project/locations/test-location/'
        'reasoningEngines/123/sessions/2'
    ),
    'update_time': '2024-12-13T12:12:12.123456Z',
    'user_id': 'user',
}
MOCK_SESSION_JSON_3 = {
    'name': (
        'projects/test-project/locations/test-location/'
        'reasoningEngines/123/sessions/3'
    ),
    'update_time': '2024-12-14T12:12:12.123456Z',
    'user_id': 'user2',
}
MOCK_EVENT_JSON = [
    {
        'name': (
            'projects/test-project/locations/test-location/'
            'reasoningEngines/123/sessions/1/events/123'
        ),
        'invocation_id': '123',
        'author': 'user',
        'timestamp': '2024-12-12T12:12:12.123456Z',
        'content': {
            'parts': [
                {'text': 'test_content'},
            ],
        },
        'actions': {
            'state_delta': {
                'key': {'value': 'test_value'},
            },
            'transfer_agent': 'agent',
        },
        'event_metadata': {
            'partial': False,
            'turn_complete': True,
            'interrupted': False,
            'branch': '',
            'long_running_tool_ids': ['tool1'],
        },
    },
]
MOCK_EVENT_JSON_2 = [
    {
        'name': (
            'projects/test-project/locations/test-location/'
            'reasoningEngines/123/sessions/2/events/123'
        ),
        'invocation_id': '222',
        'author': 'user',
        'timestamp': '2024-12-12T12:12:12.123456Z',
    },
]
MOCK_EVENT_JSON_3 = [
    {
        'name': (
            'projects/test-project/locations/test-location/'
            'reasoningEngines/123/sessions/2/events/456'
        ),
        'invocation_id': '333',
        'author': 'user',
        'timestamp': '2024-12-12T12:12:13.123456Z',
    },
]
MOCK_SESSION_JSON_PAGE1 = {
    'name': (
        'projects/test-project/locations/test-location/'
        'reasoningEngines/123/sessions/page1'
    ),
    'update_time': '2024-12-15T12:12:12.123456Z',
    'user_id': 'user_with_pages',
}
MOCK_SESSION_JSON_PAGE2 = {
    'name': (
        'projects/test-project/locations/test-location/'
        'reasoningEngines/123/sessions/page2'
    ),
    'update_time': '2024-12-16T12:12:12.123456Z',
    'user_id': 'user_with_pages',
}

MOCK_SESSION_JSON_5 = {
    'name': (
        'projects/test-project/locations/test-location/'
        'reasoningEngines/123/sessions/5'
    ),
    'update_time': '2024-12-12T12:15:12.123456Z',
    'user_id': 'user_with_many_events',
}


def _generate_mock_events_for_session_5(num_events):
  events = []
  start_time = isoparse('2024-12-12T12:12:12.123456Z')
  for i in range(num_events):
    event_time = start_time + datetime.timedelta(microseconds=i * 1000)
    events.append({
        'name': (
            'projects/test-project/locations/test-location/'
            f'reasoningEngines/123/sessions/5/events/{i}'
        ),
        'invocation_id': f'invocation_{i}',
        'author': 'user_with_many_events',
        'timestamp': event_time.isoformat().replace('+00:00', 'Z'),
    })
  return events


MANY_EVENTS_COUNT = 200
MOCK_EVENTS_JSON_5 = _generate_mock_events_for_session_5(MANY_EVENTS_COUNT)

MOCK_SESSION = Session(
    app_name='123',
    user_id='user',
    id='1',
    state=MOCK_SESSION_JSON_1['session_state'],
    last_update_time=isoparse(MOCK_SESSION_JSON_1['update_time']).timestamp(),
    events=[
        Event(
            id='123',
            invocation_id='123',
            author='user',
            timestamp=isoparse(MOCK_EVENT_JSON[0]['timestamp']).timestamp(),
            content=genai_types.Content(
                parts=[genai_types.Part(text='test_content')]
            ),
            actions=EventActions(
                transfer_to_agent='agent',
                state_delta={'key': {'value': 'test_value'}},
            ),
            partial=False,
            turn_complete=True,
            interrupted=False,
            branch='',
            long_running_tool_ids={'tool1'},
        ),
    ],
)

MOCK_SESSION_2 = Session(
    app_name='123',
    user_id='user',
    id='2',
    last_update_time=isoparse(MOCK_SESSION_JSON_2['update_time']).timestamp(),
    events=[
        Event(
            id='123',
            invocation_id='222',
            author='user',
            timestamp=isoparse(MOCK_EVENT_JSON_2[0]['timestamp']).timestamp(),
        ),
        Event(
            id='456',
            invocation_id='333',
            author='user',
            timestamp=isoparse(MOCK_EVENT_JSON_3[0]['timestamp']).timestamp(),
        ),
    ],
)


class PydanticNamespace(types.SimpleNamespace):

  def model_dump(self, exclude_none=True, mode='python'):
    d = {}
    for k, v in self.__dict__.items():
      if exclude_none and v is None:
        continue
      if isinstance(v, PydanticNamespace):
        d[k] = v.model_dump(exclude_none=exclude_none, mode=mode)
      elif isinstance(v, list):
        d[k] = [
            i.model_dump(exclude_none=exclude_none, mode=mode)
            if isinstance(i, PydanticNamespace)
            else i
            for i in v
        ]
      else:
        d[k] = v
    return d


def _convert_to_object(data):
  if isinstance(data, dict):
    kwargs = {}
    for key, value in data.items():
      if key in [
          'timestamp',
          'update_time',
          'create_time',
      ] and isinstance(value, str):
        kwargs[key] = isoparse(value)
      elif key in [
          'session_state',
          'state_delta',
          'artifact_delta',
          'custom_metadata',
          'requested_auth_configs',
      ]:
        kwargs[key] = value
      else:
        kwargs[key] = _convert_to_object(value)
    return PydanticNamespace(**kwargs)
  elif isinstance(data, list):
    return [_convert_to_object(item) for item in data]
  else:
    return data


async def to_async_iterator(data):
  for item in data:
    yield item


class MockAsyncClient:
  """Mocks the API Client."""

  def __init__(self) -> None:
    """Initializes MockClient."""
    self.session_dict: dict[str, Any] = {}
    self.event_dict: dict[str, Tuple[List[Any], Optional[str]]] = {}
    self.agent_engines = mock.AsyncMock()
    self.agent_engines.sessions.get.side_effect = self._get_session
    self.agent_engines.sessions.list.side_effect = self._list_sessions
    self.agent_engines.sessions.delete.side_effect = self._delete_session
    self.agent_engines.sessions.create.side_effect = self._create_session
    self.agent_engines.sessions.events.list.side_effect = self._list_events
    self.agent_engines.sessions.events.append.side_effect = self._append_event
    self.last_create_session_config: dict[str, Any] = {}

  async def __aenter__(self):
    """Enters the asynchronous context."""
    return self

  async def __aexit__(self, exc_type, exc_val, exc_tb):
    """Exits the asynchronous context."""
    pass

  async def _get_session(self, name: str):
    session_id = name.split('/')[-1]
    if session_id in self.session_dict:
      return _convert_to_object(self.session_dict[session_id])
    raise api_core_exceptions.NotFound(f'Session not found: {session_id}')

  async def _list_sessions(self, name: str, config: dict[str, Any]):
    filter_val = config.get('filter', '')
    user_id_match = re.search(r'user_id="([^"]+)"', filter_val)
    if user_id_match:
      user_id = user_id_match.group(1)
      if user_id == 'user_with_pages':
        return [
            _convert_to_object(MOCK_SESSION_JSON_PAGE1),
            _convert_to_object(MOCK_SESSION_JSON_PAGE2),
        ]
      return [
          _convert_to_object(session)
          for session in self.session_dict.values()
          if session['user_id'] == user_id
      ]

    # No user filter, return all sessions
    return [
        _convert_to_object(session) for session in self.session_dict.values()
    ]

  async def _delete_session(self, name: str):
    session_id = name.split('/')[-1]
    self.session_dict.pop(session_id)

  async def _create_session(
      self, name: str, user_id: str, config: dict[str, Any]
  ):
    self.last_create_session_config = config
    new_session_id = '4'
    self.session_dict[new_session_id] = {
        'name': (
            'projects/test-project/locations/test-location/'
            'reasoningEngines/123/sessions/'
            + new_session_id
        ),
        'user_id': user_id,
        'session_state': config.get('session_state', {}),
        'update_time': '2024-12-12T12:12:12.123456Z',
    }
    return _convert_to_object({
        'name': (
            'projects/test_project/locations/test_location/'
            'reasoningEngines/123/sessions/'
            + new_session_id
            + '/operations/111'
        ),
        'done': True,
        'response': self.session_dict['4'],
    })

  async def _list_events(self, name: str, **kwargs):
    session_id = name.split('/')[-1]
    events = []
    if session_id in self.event_dict:
      events_tuple = self.event_dict[session_id]
      events.extend(events_tuple[0])
      if events_tuple[1] == 'my_token':
        events.extend(MOCK_EVENT_JSON_3)

    config = kwargs.get('config', {})
    filter_str = config.get('filter', None)
    if filter_str:
      match = re.search(r'timestamp>="([^"]+)"', filter_str)
      if match:
        after_timestamp_str = match.group(1)
        after_timestamp = isoparse(after_timestamp_str)
        events = [
            event
            for event in events
            if isoparse(event['timestamp']) >= after_timestamp
        ]
    return to_async_iterator([_convert_to_object(event) for event in events])

  async def _append_event(
      self,
      name: str,
      author: str,
      invocation_id: str,
      timestamp: Any,
      config: dict[str, Any],
  ):
    session_id = name.split('/')[-1]
    event_list, token = self.event_dict.get(session_id, ([], None))
    event_id = str(len(event_list) + 1000)  # generate unique ID

    event_timestamp_str = timestamp.isoformat().replace('+00:00', 'Z')
    event_json = {
        'name': f'{name}/events/{event_id}',
        'invocation_id': invocation_id,
        'author': author,
        'timestamp': event_timestamp_str,
    }
    event_json.update(config)

    if session_id in self.session_dict:
      self.session_dict[session_id]['update_time'] = event_timestamp_str

    if session_id in self.event_dict:
      self.event_dict[session_id][0].append(event_json)
    else:
      self.event_dict[session_id] = ([event_json], None)


class MockAsyncClientWithPagination:
  """Mock client that simulates pagination requiring an open client connection.

  This mock tracks whether the client context is active and raises RuntimeError
  if iteration occurs outside the context, simulating the real httpx behavior.
  """

  def __init__(self, session_data: dict, events_pages: list[list[dict]]):
    self._session_data = session_data
    self._events_pages = events_pages
    self._context_active = False
    self.agent_engines = mock.AsyncMock()
    self.agent_engines.sessions.get.side_effect = self._get_session
    self.agent_engines.sessions.events.list.side_effect = self._list_events

  async def __aenter__(self):
    self._context_active = True
    return self

  async def __aexit__(self, exc_type, exc_val, exc_tb):
    self._context_active = False

  async def _get_session(self, name: str):
    return _convert_to_object(self._session_data)

  async def _list_events(self, name: str, **kwargs):
    return self._paginated_events_iterator()

  async def _paginated_events_iterator(self):
    for page in self._events_pages:
      for event in page:
        if not self._context_active:
          raise RuntimeError(
              'Cannot send a request, as the client has been closed.'
          )
        yield _convert_to_object(event)


def _generate_events_for_page(session_id: str, start_idx: int, count: int):
  events = []
  start_time = isoparse('2024-12-12T12:12:12.123456Z')
  for i in range(count):
    idx = start_idx + i
    event_time = start_time + datetime.timedelta(microseconds=idx * 1000)
    events.append({
        'name': (
            'projects/test-project/locations/test-location/'
            f'reasoningEngines/123/sessions/{session_id}/events/{idx}'
        ),
        'invocation_id': f'invocation_{idx}',
        'author': 'pagination_user',
        'timestamp': event_time.isoformat().replace('+00:00', 'Z'),
    })
  return events


@pytest.mark.asyncio
async def test_get_session_pagination_keeps_client_open():
  """Regression test: event iteration must occur inside the api_client context.

  This test verifies that get_session() keeps the API client open while
  iterating through paginated events. Before the fix, the events_iterator
  was consumed outside the async with block, causing RuntimeError when
  fetching subsequent pages.
  """
  session_data = {
      'name': (
          'projects/test-project/locations/test-location/'
          'reasoningEngines/123/sessions/pagination_test'
      ),
      'update_time': '2024-12-12T12:12:12.123456Z',
      'user_id': 'pagination_user',
  }
  page1_events = _generate_events_for_page('pagination_test', 0, 100)
  page2_events = _generate_events_for_page('pagination_test', 100, 100)
  page3_events = _generate_events_for_page('pagination_test', 200, 50)

  mock_client = MockAsyncClientWithPagination(
      session_data=session_data,
      events_pages=[page1_events, page2_events, page3_events],
  )

  session_service = mock_vertex_ai_session_service()

  with mock.patch.object(
      session_service, '_get_api_client', return_value=mock_client
  ):
    session = await session_service.get_session(
        app_name='123', user_id='pagination_user', session_id='pagination_test'
    )

  assert session is not None
  assert len(session.events) == 250
  assert session.events[0].invocation_id == 'invocation_0'
  assert session.events[249].invocation_id == 'invocation_249'


def mock_vertex_ai_session_service(
    project: Optional[str] = 'test-project',
    location: Optional[str] = 'test-location',
    agent_engine_id: Optional[str] = None,
    express_mode_api_key: Optional[str] = None,
):
  """Creates a mock Vertex AI Session service for testing."""
  return VertexAiSessionService(
      project=project,
      location=location,
      agent_engine_id=agent_engine_id,
      express_mode_api_key=express_mode_api_key,
  )


@pytest.fixture
def mock_api_client_instance():
  """Creates a mock API client instance for testing."""
  api_client = MockAsyncClient()
  api_client.session_dict = {
      '1': MOCK_SESSION_JSON_1,
      '2': MOCK_SESSION_JSON_2,
      '3': MOCK_SESSION_JSON_3,
      'page1': MOCK_SESSION_JSON_PAGE1,
      'page2': MOCK_SESSION_JSON_PAGE2,
  }
  api_client.event_dict = {
      '1': (copy.deepcopy(MOCK_EVENT_JSON), None),
      '2': (copy.deepcopy(MOCK_EVENT_JSON_2), 'my_token'),
  }
  return api_client


@pytest.fixture
def mock_get_api_client(mock_api_client_instance):
  """Mocks the _get_api_client method to return a mock API client."""
  with mock.patch(
      'google.adk.sessions.vertex_ai_session_service.VertexAiSessionService._get_api_client',
      return_value=mock_api_client_instance,
  ):
    yield


@pytest.mark.asyncio
async def test_initialize_with_project_location_and_api_key_error():
  with pytest.raises(ValueError) as excinfo:
    mock_vertex_ai_session_service(
        project='test-project',
        location='test-location',
        express_mode_api_key='test-api-key',
    )
  assert (
      'Cannot specify project or location and express_mode_api_key. Either use'
      ' project and location, or just the express_mode_api_key.'
      in str(excinfo.value)
  )


@pytest.mark.asyncio
@pytest.mark.usefixtures('mock_get_api_client')
@pytest.mark.parametrize('agent_engine_id', [None, '123'])
async def test_get_empty_session(agent_engine_id):
  session_service = mock_vertex_ai_session_service(agent_engine_id)
  with pytest.raises(api_core_exceptions.NotFound) as excinfo:
    await session_service.get_session(
        app_name='123', user_id='user', session_id='0'
    )
  assert str(excinfo.value) == '404 Session not found: 0'


@pytest.mark.asyncio
@pytest.mark.usefixtures('mock_get_api_client')
@pytest.mark.parametrize('agent_engine_id', [None, '123'])
async def test_get_another_user_session(agent_engine_id):
  session_service = mock_vertex_ai_session_service(agent_engine_id)
  with pytest.raises(ValueError) as excinfo:
    await session_service.get_session(
        app_name='123', user_id='user2', session_id='1'
    )
  assert str(excinfo.value) == 'Session 1 does not belong to user user2.'


@pytest.mark.asyncio
@pytest.mark.usefixtures('mock_get_api_client')
async def test_get_and_delete_session():
  session_service = mock_vertex_ai_session_service()

  assert (
      await session_service.get_session(
          app_name='123', user_id='user', session_id='1'
      )
      == MOCK_SESSION
  )

  await session_service.delete_session(
      app_name='123', user_id='user', session_id='1'
  )
  with pytest.raises(api_core_exceptions.NotFound) as excinfo:
    await session_service.get_session(
        app_name='123', user_id='user', session_id='1'
    )
  assert str(excinfo.value) == '404 Session not found: 1'


@pytest.mark.asyncio
@pytest.mark.usefixtures('mock_get_api_client')
async def test_get_session_with_page_token():
  session_service = mock_vertex_ai_session_service()

  assert (
      await session_service.get_session(
          app_name='123', user_id='user', session_id='2'
      )
      == MOCK_SESSION_2
  )


@pytest.mark.asyncio
@pytest.mark.usefixtures('mock_get_api_client')
async def test_get_session_with_after_timestamp_filter():
  session_service = mock_vertex_ai_session_service()
  session = await session_service.get_session(
      app_name='123',
      user_id='user',
      session_id='2',
      config=GetSessionConfig(
          after_timestamp=isoparse('2024-12-12T12:12:13.0Z').timestamp()
      ),
  )
  assert session is not None
  assert len(session.events) == 1
  assert session.events[0].id == '456'


@pytest.mark.asyncio
@pytest.mark.usefixtures('mock_get_api_client')
async def test_get_session_keeps_events_newer_than_update_time(
    mock_api_client_instance: MockAsyncClient,
) -> None:
  future_event_time = isoparse(
      MOCK_SESSION_JSON_1['update_time']
  ) + datetime.timedelta(seconds=1)
  event = mock_api_client_instance.event_dict['1'][0][0]
  event['timestamp'] = future_event_time.isoformat().replace('+00:00', 'Z')
  session_service = mock_vertex_ai_session_service()

  session = await session_service.get_session(
      app_name='123', user_id='user', session_id='1'
  )

  assert session is not None
  assert len(session.events) == 1
  assert session.events[0].timestamp == future_event_time.timestamp()
  assert session.events[0].timestamp > session.last_update_time, (
      'Event timestamp should exceed session update_time to guard against'
      ' filtering.'
  )


@pytest.mark.asyncio
@pytest.mark.usefixtures('mock_get_api_client')
async def test_get_session_with_many_events(mock_api_client_instance):
  mock_api_client_instance.session_dict['5'] = MOCK_SESSION_JSON_5
  mock_api_client_instance.event_dict['5'] = (
      copy.deepcopy(MOCK_EVENTS_JSON_5),
      None,
  )
  session_service = mock_vertex_ai_session_service()
  session = await session_service.get_session(
      app_name='123', user_id='user_with_many_events', session_id='5'
  )
  assert session is not None
  assert len(session.events) == MANY_EVENTS_COUNT


@pytest.mark.asyncio
@pytest.mark.usefixtures('mock_get_api_client')
async def test_list_sessions():
  session_service = mock_vertex_ai_session_service()
  sessions = await session_service.list_sessions(app_name='123', user_id='user')
  assert len(sessions.sessions) == 2
  assert sessions.sessions[0].id == '1'
  assert sessions.sessions[1].id == '2'


@pytest.mark.asyncio
@pytest.mark.usefixtures('mock_get_api_client')
async def test_list_sessions_with_pagination():
  session_service = mock_vertex_ai_session_service()
  sessions = await session_service.list_sessions(
      app_name='123', user_id='user_with_pages'
  )
  assert len(sessions.sessions) == 2
  assert sessions.sessions[0].id == 'page1'
  assert sessions.sessions[1].id == 'page2'


@pytest.mark.asyncio
@pytest.mark.usefixtures('mock_get_api_client')
async def test_list_sessions_all_users():
  session_service = mock_vertex_ai_session_service()
  sessions = await session_service.list_sessions(app_name='123', user_id=None)
  assert len(sessions.sessions) == 5
  assert {s.id for s in sessions.sessions} == {
      '1',
      '2',
      '3',
      'page1',
      'page2',
  }


@pytest.mark.asyncio
@pytest.mark.usefixtures('mock_get_api_client')
async def test_create_session():
  session_service = mock_vertex_ai_session_service()

  state = {'key': 'value'}
  session = await session_service.create_session(
      app_name='123', user_id='user', state=state
  )
  assert session.state == state
  assert session.app_name == '123'
  assert session.user_id == 'user'
  assert session.last_update_time is not None

  session_id = session.id
  assert session == await session_service.get_session(
      app_name='123', user_id='user', session_id=session_id
  )


@pytest.mark.asyncio
@pytest.mark.usefixtures('mock_get_api_client')
async def test_create_session_with_custom_session_id():
  session_service = mock_vertex_ai_session_service()

  with pytest.raises(ValueError) as excinfo:
    await session_service.create_session(
        app_name='123', user_id='user', session_id='1'
    )
  assert str(excinfo.value) == (
      'User-provided Session id is not supported for VertexAISessionService.'
  )


@pytest.mark.asyncio
@pytest.mark.usefixtures('mock_get_api_client')
async def test_create_session_with_custom_config(mock_api_client_instance):
  session_service = mock_vertex_ai_session_service()

  expire_time = '2025-12-12T12:12:12.123456Z'
  await session_service.create_session(
      app_name='123', user_id='user', expire_time=expire_time
  )
  assert (
      mock_api_client_instance.last_create_session_config['expire_time']
      == expire_time
  )


@pytest.mark.asyncio
@pytest.mark.usefixtures('mock_get_api_client')
async def test_append_event():
  session_service = mock_vertex_ai_session_service()
  session_before_append = await session_service.get_session(
      app_name='123', user_id='user', session_id='1'
  )
  event_to_append = Event(
      invocation_id='new_invocation',
      author='model',
      timestamp=1734005533.0,
      content=genai_types.Content(parts=[genai_types.Part(text='new_content')]),
      actions=EventActions(
          transfer_to_agent='another_agent',
          state_delta={'new_key': 'new_value'},
          skip_summarization=True,
          requested_auth_configs={
              'test_auth': AuthConfig(
                  auth_scheme=auth_schemes.OAuth2(
                      flows=openapi_models.OAuthFlows(
                          implicit=openapi_models.OAuthFlowImplicit(
                              authorizationUrl='http://test.com/auth',
                              scopes={},
                          )
                      )
                  ),
              ),
          },
      ),
      error_code='1',
      error_message='test_error',
      branch='test_branch',
      custom_metadata={'custom': 'data'},
      long_running_tool_ids={'tool2'},
  )

  await session_service.append_event(session_before_append, event_to_append)

  retrieved_session = await session_service.get_session(
      app_name='123', user_id='user', session_id='1'
  )

  assert len(retrieved_session.events) == 2
  event_to_append.id = retrieved_session.events[1].id
  assert retrieved_session.events[1] == event_to_append